This study is an NIH Neonatal Network multicenter, randomized, double masked clinical trial "Antenatal Phenobarbital in the Prevention of Neonatal Intracranial Hemorrhage." A standardized dosing regimen of phenobarbital and placebo will be employed in this large multicenter trial and will test for the efficacy and side effects of antenatal phenobarbital therapy in the prevention of neonatal intracranial hemorrhage.